Slain American Michael Sharp told his mother two years ago he was committed to helping the Congolese people in his role as a U.N. investigator and was "not afraid to die."

"He said the hardest thing for him was to think about pain he would cause his family," Michele Miller Sharp said in a telephone interview on Thursday from her home in Kansas. "I told him we all supported him and we would handle any pain and he should continue his work."

Sharp's mother learned of his death on her birthday. United Nations peacekeepers in Congo this week discovered his body and that of Zaida Catalan, a Swedish national, who had been missing in an area engulfed in violence.

Sharp, 34, was in a group of experts monitoring sanctions imposed on Congo by the U.N. Security Council when he and others were kidnapped this month in Kasai Central province.

Despite the risks, Sharp's parents, who live outside Wichita, "were fully supportive of him because he was passionate. This was his calling," said his father, John E. Sharp, 65.

"We were not about to step in the way of that in spite of our fears," he added. "Although we hoped and prayed something like this would never happen, we knew it was a possibility."

Michael Sharp was raised in Indiana and learned from his Mennonite Christian faith the core values of peace building and nonviolence, his 62-year-old mother said. After studying history in college, Michael headed to Germany, where he volunteered and then earned a master's degree in international conflict resolution.

Sharp resided in Albuquerque, New Mexico when he was on breaks from his work. In Congo, he worked three years building relationships with militia leaders, convincing them to lay down their weapons and release the children they had dragooned into being soldiers.

"That was his passion, to work at helping this war-torn country," said his mother. "He cared deeply about the Congolese people."

Michael joined the U.N. in 2015 as a militia group expert, presenting information to the Security Council and making recommendations on sanctions, his parents said.

Colleagues told his parents that Congolese militia leaders respected their son, who would travel for miles, unarmed, to meet them under a banana tree and just listen to them.

Michael would no doubt be amazed at the fuss about him as he was very unassuming and humble, his father said. While he understood the risks involved, he worried more about the effect his death might have on his family.

"About two years ago, he sat down beside me and said, 'Mom you know I don't have death wish in the work I do, but I want you to know I'm not afraid to die either.'" his mother said. She said the family supported him.

"From a toddler on up, every day was lived to the fullest," she added.

Meanwhile, his parents and two sisters wait for the return of Michael's body to the United States, where U.S. officials will perform an autopsy. His parents said U.N. officials have been in constant communication with them.

U.N. Secretary-General Antonio Guterres on Tuesday said the world body would "do everything possible to ensure that justice is done." U.S. Ambassador Nikki Haley called the death senseless.

"Michael was working on the front lines of what we try to do at the United Nations every day: find problems and fix them," she said in a statement. "He selflessly put himself in harm’s way to try to make a difference in the lives of the Congolese people."

Congo's Kasai Central region is the center of the Kamuina Nsapu insurgency that has now spread to five provinces in the loosely governed Central African country.

The parents said they hope the U.N. doesn't abandon its work in Congo due to their son's death. "We would not want this tragedy to be compounded by withdrawal from that region," the father John said. "We also want the U.S. to continue its funding to the U.N."